Flashcards in Principles of Neuroscience Lecture 4, Development of the nervous system Deck (19)
What are the layers in an embryo?
From which cells does the neural tube form?
Neural plate cells form a layer on the ectoderm
Describe the process of neurulation
The neural plate cells on either side of the primitive streak rise up and fuse at the top, forming a tube. This tube is called the neural tube. This goes on to form the spinal cord.
What disorders can occur with neurulation, and how do they arise?
When the neural tube does not close up all the way up the spine.
This causes severe disorders such as:
Spina bifida (lumbar region)
Describe the sections that the developing brain forms
Caudal neural tube: spinal cord
Describe the further segmentation of the prosencephalon
Describe the further segmentation of the rhombencephalon
Two greater sections :
7 sections all up
What does the spinal cord form out of?
The caudal neural tube
What is the name for the cells present at the top of the neural tube during development?
What is their function?
Neural crest cells. These cells migrate and go on to form many important cell types
What is Somite?
Developing muscle and bone
Describe the process of neural crest migration
Neural crest cells follow specific paths through the embryo
- under the skin to form the dorsal root ganglia
- through the Somite to form sympathetic ganglia
Eg. Innervation of the gut; enteric nervous system
How does the cortex / cells of the brain form?
It starts with the neuroepithelium that is one cell thick.
This neuroepithelium adds cells that migrate away to form the cortex.
What is the ventricular zone?
Down the bottom, where neurons are being born. Stem cells are here
What are radial glia?
Their processes act as a guide along which neurons migrate down to form the cortex.
What does the notochord go on to form?
The centre of the vertebral body
What is sonic hedgehog?
Chemical that sets up a gradient and thus polarity in the neural tube, indicating where neurons should grow.
Describe the process of axonal growth
Axons aren't present when the neuron first develops
What are growth cones made out of?
They are a dynamic cytoskeleton structure